Twin tube shock with adjustable pressure regulation

ABSTRACT

A fluid damper having a damper housing with a first and a second fluid volume, and a damping piston located within the damper and separating the first and second fluid volume. The damper piston has a piston fluid pathway formed therethrough and between the first and second fluid volume. The fluid damper includes a fluid accumulator having an accumulator fluid volume. The fluid damper has a first fluid pathway extending between the first fluid volume and the accumulator fluid volume, and the fluid damper has a second fluid pathway extending between the second fluid volume and the accumulator fluid volume. A flow control valve is located in at least one of the first and the second fluid pathways, and the flow control valve has a non-zero threshold value.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Application claims priority to and benefit of U.S. ProvisionalPatent Application No. 62/623,430, filed on Jan. 29, 2018, entitled“TWIN TUBE SHOCK WITH ADJUSTABLE PRESSURE REGULATION” by Joshua Coaplenet al., with Attorney Docket No. FOX-2016-18.PRO2, which is incorporatedherein, in its entirety, by reference.

This application claims priority to and benefit of U.S. patentapplication Ser. No. 15/882,604, filed on Jan. 29, 2018, entitled “TWINTUBE SHOCK WITH ADJUSTABLE PRESSURE REGULATION” by Joshua Coaplen etal., with Attorney Docket No. FOX-2016-18US, which is incorporatedherein, in its entirety, by reference.

U.S. patent application Ser. No. 15/882,604 claims priority to andbenefit of U.S. Provisional Patent Application No. 62/452,264, filed onJan. 30, 2017, entitled “TWIN TUBE SHOCK WITH ADJUSTABLE PRESSUREREGULATION” by Joshua Coaplen et al., with Attorney Docket No.FOX-2016-18.PRO, which is incorporated herein, in its entirety, byreference.

BACKGROUND OF THE INVENTION Field of the Invention

The present disclosure relates to the field of dampening devices forvehicles, such as bicycles, motorcycles, unicycles, and three or greaterwheeled vehicles.

Description of Related Art

Vehicle suspension systems typically include a spring component orcomponents and a damping component or components. Typically, mechanicalsprings, such as metal leaf or helical springs, have been used inconjunction with some type of viscous fluid based damping mechanismmounted functionally in parallel. Dampers commonly include a housingforming a generally fixed volume chamber having a piston therein, whichis attached to a suspension component by a rod or shaft attached theretoand extending from the chamber, and which piston moves axially withinthe chamber to dampen the impact of a suspension force event, such as abump or obstruction in terrain over which the vehicle is moving. Thedamper typically operates by restricting the flow of working fluidacross or through the piston as it traverses the chamber to slow themovement of a piston therein, especially during a compression stroke.The fluid flow restriction elements, because they are located on thepiston which is sealed within the housing, are typically not useradjustable, and are also typically preset for “average” use conditionsand thus are not adaptable to varying conditions.

One variant of the above described damper construct employs a gasreservoir which is coupled to the fluid of the damper across a floatingpiston. The gas reservoir provides a pressure reservoir source which isuseful to cause the piston in the damper chamber to return to a steadystate position after a compression event, also known as rebounding.During a compression event, the physical size of the fluid volume on therebound side of the piston may rapidly increase, and if the fluid flowrate into the rebound chamber is not sufficiently fast, the pressurewill drop in the fluid on the rebound side of the chamber to a levelwhere any gas, such as air, entrained in the fluid will aspirate toreform a gas state thereof, causing cavitation in the fluid. This cancause serious disruption in the proper operation of the damper, andunacceptable noise emanating from the damper.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentinvention can be understood in detail, a more particular description ofthe invention, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments.

FIG. 1 is a schematic perspective view of an embodiment of the fluiddamper hereof, in accordance with an embodiment.

FIG. 2 is a sectional view of the fluid damper of FIG. 1, showing thedetails of the interior thereof, in accordance with an embodiment.

FIG. 3 is a sectional view of the fluid damper of FIG. 2 at section 3-3,in accordance with an embodiment.

FIG. 4 is a sectional view of the fluid damper of FIG. 2 at section 4-4,in accordance with an embodiment.

FIG. 5 is a sectional view of the fluid damper of FIG. 2 at section 5-5,in accordance with an embodiment.

FIG. 6 is a sectional view of the fluid damper of FIG. 2 at section 6-6,in accordance with an embodiment.

FIG. 7 is a schematic depiction of a twin tube shock in accordance withone embodiment of the present invention.

FIG. 8 is a back-perspective view of twin tube shock in accordance withone embodiment of the present invention.

FIG. 9 is a cross-sectional view illustrating internal features of atwin tube shock in accordance with one embodiment of the presentinvention.

FIG. 10 is a close-up view, of a portion of the cross-sectional view ofFIG. 9, illustrating internal features such as the outer tube damper andthe inner tube damper in accordance with one embodiment of the presentinvention.

FIG. 11A is a top view of a twin tube shock, in accordance with oneembodiment of the present invention, including a section planecorresponding to the cross-sectional view provided in FIG. 11B.

FIG. 11B is a cross-sectional view, taken through the section planeshown in FIG. 11A, showing a fluid connection path extending from themain damper body to the rebound base valve (schematically depicted as2014 in FIG. 7), in accordance with one embodiment of the presentinvention.

FIG. 12A is a top view of a twin tube shock, in accordance with oneembodiment of the present invention, including a section planecorresponding to the cross-sectional view provided in FIG. 12B.

FIG. 12B is a cross-sectional view, taken through the section planeshown in FIG. 12A, showing a fluid connection path extending from themain damper body to the compression base valve (schematically depictedas 2010 in FIG. 7), in accordance with one embodiment of the presentinvention.

FIG. 13A is a partial front perspective view of a twin tube shock, inaccordance with one embodiment of the present invention, including asection plane corresponding to the cross-sectional view provided in FIG.13B.

FIG. 13B is a cross-sectional view, taken through the section planeshown in FIG. 13A, showing a fluid connection path extending from themain damper body to the rebound base valve (schematically depicted as2014 in FIG. 7), in accordance with one embodiment of the presentinvention.

FIG. 14A is a partial front perspective view of a twin tube shock, inaccordance with one embodiment of the present invention, including asection plane corresponding to the cross-sectional view provided in FIG.14B.

FIG. 14B is a cross-sectional view, taken through the section planeshown in FIG. 14A, showing a fluid connection path extending from themain damper body to the compression base valve (schematically depictedas 2010 in FIG. 7), in accordance with one embodiment of the presentinvention.

FIG. 15 is a cross-sectional view of a base valve including a selectorshaft, in accordance with one embodiment of the present invention.

FIG. 16 is a perspective views of components comprising the base valveof FIG. 15 including compression ports, in accordance with oneembodiment of the present invention.

FIG. 17 is a perspective views of components comprising the base valveof FIG. 15 including rebound ports, in accordance with one embodiment ofthe present invention.

FIG. 18A is a perspective view of a base valve, in accordance with oneembodiment of the present invention.

FIG. 18B is a perspective view of a selector valve for use with the basevalve of FIG. 18A, in accordance with one embodiment of the presentinvention.

FIG. 18C is a perspective view of the base valve of FIG. 18A having theselector valve of FIG. 18B coupled thereto, in accordance with oneembodiment of the present invention.

FIG. 19A is a perspective view of the base valve of FIG. 18A having theselector valve of FIG. 18B coupled thereto in a first position toselectively control the flow of fluid through the base valve, inaccordance with one embodiment of the present invention.

FIG. 19B is a perspective view of the base valve of FIG. 18A having theselector valve of FIG. 18B coupled thereto in a second position toselectively control the flow of fluid through the base valve, inaccordance with one embodiment of the present invention.

FIG. 19C is a perspective view of the base valve of FIG. 18A having theselector valve of FIG. 18B coupled thereto in a third position toselectively control the flow of fluid through the base valve, inaccordance with one embodiment of the present invention.

FIG. 20 is a schematic diagram of a twin tube shock including acontrolled bypass fluid path extending between the compression side andthe rebound side, but which does not flow through the fluid accumulator,in accordance with an embodiment of the present invention.

FIG. 21 is a schematic depiction of a twin tube shock in accordance withone embodiment of the present invention.

FIG. 22 is a schematic diagram of a twin tube shock including acontrolled bypass fluid path extending between the compression side andthe rebound side, but which does not flow through the fluid accumulator,in accordance with an embodiment of the present invention.

FIG. 23 is a schematic depiction of a twin tube shock in accordance withone embodiment of the present invention.

FIG. 24 is a schematic diagram of a twin tube shock including acontrolled bypass fluid path extending between the compression side andthe rebound side, but which does not flow through the fluid accumulator,in accordance with an embodiment of the present invention.

FIG. 25 is a schematic depiction of a twin tube shock in accordance withone embodiment of the present invention.

FIG. 26 is a schematic diagram of a twin tube shock including acontrolled bypass fluid path extending between the compression side andthe rebound side, but which does not flow through the fluid accumulator,in accordance with an embodiment of the present invention.

FIG. 27 is a schematic depiction of a twin tube shock in accordance withone embodiment of the present invention.

FIG. 28 is a schematic diagram of a twin tube shock including acontrolled bypass fluid path extending between the compression side andthe rebound side, but which does not flow through the fluid accumulator,in accordance with an embodiment of the present invention.

FIG. 29 is a schematic depiction of a twin tube shock in accordance withone embodiment of the present invention.

FIG. 30 is a schematic diagram of a twin tube shock including acontrolled bypass fluid path extending between the compression side andthe rebound side, but which does not flow through the fluid accumulator,in accordance with an embodiment of the present invention.

DESCRIPTION OF EMBODIMENTS

A dampening device, such as a strut or shock absorber, generallyincludes a tube shaped housing within which a piston, disposed on an endof a piston rod which extends outwardly of the housing, moves inresponse to forces imposed on the housing and the rod, the movementdampened by the presence of a fluid in the housing passing throughvalved openings in the piston, a secondary reservoir fluidly connectedto the tube, and a connecting portion interconnecting the fluid portionof the tube and the secondary reservoir. Fluid is enabled to movebetween the housing and the secondary reservoir, in response to movementof the piston inwardly and outwardly of the housing. Fluid on one sideof the piston is able to move through the piston, to the fluid volume onthe opposite side of the piston, through one or more check valves withinthe body of the piston. The rate of fluid flow between the fluid volumeson either side of the piston, and between the fluid volumes in thedampening member housing and the secondary reservoir, affects thedampening effect of the dampening device upon the vehicle in which it isused. One example of a twin tube damper is found in commonly-owned,pending patent application filed on Apr. 13, 2015 having U.S. Ser. No.14/685,348, and entitled “TWIN TUBE DAMPER WITH REMOTE GAS RESERVOIR” byChristopher Paul Cox, having Attorney Docket Number FOX-0067US, which isherein incorporated by reference in its entirety.

Referring now to FIG. 1, a perspective view of the exterior structure ofsuch a damping cylinder 20 and a remote reservoir 30 are fluidlyinterconnected through a valved interconnection housing 40 which alsobounds one end of the internal pressurizable volumes of the dampingcylinder 20 and of the remote reservoir 30. The valved interconnectionhousing also includes an attachment projection 50 through which abushing 52 extends, for attaching the attachment projection 50, and thusone end of the damping cylinder 20, to a suspension or vehicle framecomponent. At the upper end 22 of the damping cylinder 20 opposite tothe connection thereof to the valved interconnection housing 40, apiston rod 60 extends. The distal end 62 of the piston rod 60 surroundsa bushed opening 64, through which a bushing 66 extends. The distal end62 of the piston rod 60 is thereby interconnected to the other of one ofa vehicle frame or suspension components via the bushing 66.

The damper 10 is also configured to carry a secondary spring element,specifically a mechanical coil spring 70, for clarity of the laterFigures shown only in FIG. 2, which provides additional rigidity andcompression damping and rebounding force in the damper 10. In thisembodiment, the mechanical coil spring 70 is bifurcated into an upperspring 72 and a lower spring 74. The upper spring 72 extends between,and bears against, an upper annular spring plate 76 secured to the outersurface of the body of the damping cylinder 20, and an upper surface 78of an intermediate annular spring plate 80, which extendscircumferentially outwardly around the circumference of a spring sleeve82, which is configured and sized to fit over, but freely move in anaxial direction over, the damping cylinder 20. The second, lower spring74 extends from contact with the underside annular surface 84 of theintermediate annular spring plate 80, and into contact with a lowerannular spring flange 86 extending outwardly from, and circumferentiallyaround, the piston rod 60 adjacent to, but spaced in the dampingcylinder 20 direction from, the distal end 62 thereof.

Referring again to FIG. 1, the valved interconnection housing 40 alsoincludes two extensions or bosses 42, 44 which provide valved flowpassages (not shown in this Figure) which extend from the dampingcylinder 20 side to the remote reservoir 30 side of the valvedinterconnection housing 40, and, extending approximately normal to theextending direction of bosses 42, 44, an internally threaded boss 46,into which the upper end 22 of the damping cylinder 20 is secured andwhich is fluidly connected to the flow passages and a second boss 48,having a threaded projection 49 thereon (FIG. 2), over which the upperend 32 of the remote reservoir 30 body is secured and the interior ofwhich is fluidly connected to the flow passage. Thus, as will be shownin greater detail in regard to FIG. 2 hereof, upon the movement of thepiston rod 60 inwardly of the damping cylinder 20, fluid within thedamping cylinder 20 may flow from the compression volume (also referredto as a compression chamber) in the interior of the damping cylinder 20,through a flow passage in the valved interconnection housing 40, andhence into the remote reservoir 30. Also, during a compression stroke,valves 90, 92 enable flow of fluid through the valved interconnectionhousing 40, and communication of fluid pressure, at the gas reservoirpressure, to the rebound side of the piston. Likewise, upon retractionof the piston rod 60 from the body of the damping cylinder 20, fluid mayflow from adjacent the gas piston 36 in the remote reservoir 30, througha flow passage in the valved interconnection housing 40 and then intothe compression volume of the damping cylinder 20, and fluid, and fluidmay flow from the rebound side of the damping cylinder 20 to the remotereservoir 30, i.e., back through the valved interconnection housing 40.The selectable restriction to flow of fluid inwardly and outwardly ofthe remote reservoir 30 is provided by valves 90, 92, shownschematically on FIG. 1, which will be discussed in further detailherein.

Referring now to FIG. 2, details of the interrelationship of the dampingcylinder 20 and the remote reservoir 30 are shown, wherein the dampingcylinder 20, the remote reservoir 30, and the valved interconnectionhousing 40 are shown in cutaway across a portion of the valvedinterconnection housing 40 intermediate of the two valves 90, 92thereon. As discussed previously herein, a mechanical coil spring 70,having an upper spring 72 and a lower spring 74, is disposed about theexterior of the damping cylinder 20. The damper 10 has a main volume100, surrounded by an inner tube 102, and an annular volume 106 (FIGS. 3and 5), formed between the inner tube 102 and an outer tube 104. Theopenings in the internally threaded boss 46 and second boss 48 of theinterconnection housing 40 enable fluid communication by and between theinner tube 102 volume and the annular volume 106 of the damping cylinder20 and the remote reservoir 30, as will be described in detail herein.

Referring now to FIGS. 2 to 6, the construction of the damping cylinder20 is shown. It should be noted that the present invention is wellsuited to use with any of various types of twin tube dampers. Althoughnumerous features are shown in FIG. 2 and discussed herein (e.g.: amechanical coil spring member 70 having upper spring 72 and lower spring74; internal bypass openings 110 a-d; and the like), the presentinvention is also well suited to use with a twin tube damper which mayor may not include such features. That is, the various embodiments ofthe present invention are not limited to use with a twin tube damperhaving all of the features depicted in the twin tube damper of FIG. 2.

Referring again to FIG. 2, the fluid volume within the inner tube 102 isbifurcated by the piston 120 into two variable volumes: a compressionvolume 108 (also referred to as a compression chamber) between thepiston 120 and the opening of the damping cylinder 20 into the valvedinterconnection housing 40, and a rebound volume 109 (also referred toas a rebound chamber) which extends between the opposite side of thepiston 120 to the inner face of seal housing 151. Additionally, toprovide one of the fluid pathways for fluid communication between thecompression volume 108 and the rebound volume 109, a plurality ofopenings 110 a-d are provided through the wall of the inner tube 102between the inner volume of the inner tube 102 and the annular volume106, and a plurality of passages 112 (the plurality shown in FIG. 6) areprovided at the interconnection location of inner tube 102 and the sealhousing 151. Thus, during movement of the piston 120 within the innertube 102, fluid may flow between the compression volume 108 and therebound volume 109 portions of the inner tube 102 as the actual volume(size) of those volumes change as the piston 120 moves within the innertube 102, from openings 110 a-d through the annular volume 106 and intothe rebound volume 109 through the passages 112, and, if the piston 120is disposed intermediate of the openings 110 a-d, for example, whereinopening 110 a is on one side of the piston 120 and opening 110 d is onanother side of the piston 120, flow may occur therethrough between therebound volume 109 and the compression volume 108. In one embodiment,these un-valved openings 110, and passages 112 thus provide a direct,though restricted by the cross section and of the openings, flow pathwayfor fluid between the compression volume 108 and the rebound volume 109during piston 120 movement within the inner tube 102.

The openings 110 are configured as a plurality of larger openings 110 aand 110 b and smaller openings 110 c and 110 d and are provided in andthrough the wall of the inner tube 102 to communicate the main volume100 (the compression volume 108 and the rebound volume 109) of thedamper 10 with the annular volume 106 of the damper 10. In thisembodiment, as shown in FIG. 2, a large upper and a large lower opening,110 a, 110 b are disposed through the inner tube 102 along the sides ofthe inner tube 102 to either side of the inner tube 102, i.e.,diametrically opposed across the circumference of the inner tube 102,and two smaller upper and lower openings 110 c and 110 d are locatedtherebetween, i.e., between each pair of larger openings 110 a and 110b. Additionally, the openings 110 a-d on one side of the inner tube 102,e.g., to the right hand side of the inner tube 102 are offset, in thedirection of the stroke of the piston 120 toward the valvedinterconnection housing 40, as compared to the location of the openings110 a-d to the left hand side of the inner tube 102, but the spacingbetween the adjacent openings 110 a-d to either side of the inner tube102 is the same. As a result, the openings are staggered along thelongitudinal axis L of the inner tube 102. Thus, when a piston, such aspiston 120 located within inner tube 102 traverses within the inner tube102 in the direction of the valved interconnection housing 40,individual ones of the openings 110 a-d will be encountered andselectively blocked by the piston 120, and as the piston 120 passes anopening, the number of openings 110 a-d available to form acommunication path from the annular volume 106 from the compressionvolume 108 on one side of the piston 120 to the rebound volume 109 onthe other side of the piston 120, and vice-versa, will change.

Twin Tube Shock with Adjustable Pressure Regulation

In a twin tube style shock with adjustable damping, the thresholdforce/pressure at the maximum damping setting (sometimes referred to asa “hard mode”) has traditionally been controlled by a compressionvalve(s) of the main damping piston. More specifically, the maximumdamping setting is achieved through valving of the main damping piston,which strongly restricts the flow of fluid through the main dampingpiston. In one such approach, the compression valve is comprised of atightly compressed (or stiff) shim stack, or other restrictive valvingmechanism which is utilized to restrict and control the flow of fluidthrough the main damping piston. However, the “stiffness” of the valvingof the main damping piston affects the damping curve for the twin tubeshock at all settings, as the valving of the main damping piston is nottraditionally externally adjustable. The consequence of this approach isthat even when it is desired to place the twin tube shock in a minimumdamping setting (sometimes referred to as a “soft mode”), therestrictive valving of the main damping piston prevents the twin tubeshock from achieving an adequately soft setting. That is, the minimumdamping that can be obtained for the twin tube shock is limited by thevalving of the main damping piston. This situation is unique to twintube style shocks as there is a fluid connection between therebound-side of the main damping piston and a fluid accumulator. It willbe understood to those of ordinary skill in the art, that a fluidaccumulator, sometimes referred to as a reservoir, may typically becomprised, as depicted in FIG. 7 and FIG. 20, of a pressurizable gasvolume 5 which is separated from an accumulator fluid volume 6 by sometype of separation member 7. In some embodiments, the separation member7 may be comprised of a floating piston.

Even in a state where there is little or no flow through a compressionbase valve (maximum possible base valve damping) fluid can still flowthrough the valving of the main damping piston, and then flow throughthe fluid connection between the rebound-side of the main damping pistonand the fluid accumulator. Thus, in conventional twin tube shocks, thevalving of the main damping piston dictates the stiffness of the hardmode, while also limiting the softness that can be achieved by the shockwhen in the soft mode.

In embodiments of the present invention, a twin tube shock is providedwherein the softness of a soft mode setting is not governed by thevalving of the main damping piston. More specifically, in variousembodiments of the present invention, the fluid connection between therebound side of the main damping piston and the fluid accumulator is“switched off” in the hard mode (i.e. the maximum compression dampingstate). When this fluid connection is “switched off”, the valving of themain damping piston no longer controls the maximum possible thresholdforce for the twin tube shock. Instead, in various embodiments of thepresent invention, the maximum possible threshold force for the twintube shock is controlled by a selectable compression base valve. As aresult, in an embodiment of the present invention, the valving of themain damping piston is selected such that is has a non-maximumcompression damping setting. In such an embodiment, the valving of themain damping piston does not undesirably limit the softness of the softmode for the twin tube shock. Hence, embodiments of the presentinvention provide a twin tube shock which can achieve a desired maximumdamping setting (hard mode), and wherein the softness of a soft modesetting is not governed by valving of the main damping piston. It willbe understood that many riders may judge the performance of a shockabsorber based on the shock absorber's performance when in a softsetting. Such a soft setting may be employed, for example, when ridingvery quickly (e.g. downhill) and over bumpy terrain. Unlike,conventional twin tube shocks, embodiments of the present inventionprovide favorable soft mode operation, while still enabling a desiredmaximum damping setting when in hard mode.

Referring now to FIG. 7, a schematic depiction of a twin tube shock 2001in accordance with one embodiment of the present invention is shown. Inthe embodiment of FIG. 7, twin tube shock 2001 is comprised of a twintube style main damper body 2002 (also referred to as a housing).Additionally, the present embodiment further comprises a damper shaft2004 and a main damping piston 2006 which is reciprocatingly disposedwithin the main damper body 2002. Main damping piston 2006 divides thevolume within main damper body 2002 into a first fluid volume and asecond fluid volume. As an example, main damping piston 2006 separates afirst fluid volume, for example, compression side 2003 from a secondfluid volume, for example, rebound side 2005. Damping piston valving2008 of main damping piston 2006 is schematically depicted by an arrow.It will be understood that damping piston valving 2008 may comprisecompression and/or rebound valving. In the present application, a fluidpathway which passes through main damping piston 2006 and, in someembodiments, damping piston valving 2008, is referred to as a pistonfluid pathway. In various embodiments of the present invention, thepiston fluid pathway will allow, under certain conditions, damping fluidto flow through main damping piston 2006 (and, in one embodiment,damping piston valving 2008) from the compression side 2003 to therebound side 2005. In various embodiments of the present invention, thepiston fluid pathway will allow, under certain conditions, damping fluidto flow through main damping piston 2006 (and, in one embodiment,damping piston valving 2008) from the rebound side 2005 to thecompression side 2003. Also, in various embodiments of the presentinvention, the piston fluid pathway will allow, under certainconditions, damping fluid to flow through main damping piston 2006 (and,in one embodiment, damping piston valving 2008) from the compressionside 2003 to the rebound side 2005, and the same piston fluid pathway(or a separate piston fluid pathway) will also allow, under certainconditions, damping fluid to flow from the rebound side 2005 to thecompression side 2003.

In various embodiments of the present invention, damping piston 2008 hasmultiple piston fluid pathways formed therethrough. In such anembodiment, any one or more of the multiple piston fluid pathways may ormay not have damping piston valving associated therewith. It will beunderstood to those of ordinary skill in the art that damping pistonvalving 2008 can be comprised of any of numerous types of valvecomponents or various configurations of such valve components. It willfurther be understood to those of ordinary skill in the art, that whendamping piston valving 2008 is present, damping piston valving 2008 willallow the flow of fluid therethrough once the fluid pressure exceeds athreshold value for damping piston valving 2008. It should further benoted that a specific threshold value for damping piston valving 2008can be obtained through various techniques known to those of ordinaryskill in the art.

Twin tube shock 2001 of the present embodiment further comprises acompression base valve 2010. As schematically depicted within the dottedbox enclosing compression base valve 2010, compression base valve 2010is comprised of various valve components which selectively fluidicallycouple compression side 2003 and fluid accumulator 2012. It will beunderstood to those of ordinary skill in the art that compression basevalve 2010 can be comprised of any of numerous types of valve componentsor various configurations of such valve components. In embodiments ofthe present invention, compression base valve 2010 will allow the flowof fluid therethrough once the fluid pressure exceeds a threshold valuefor compression base valve 2010. In various embodiments of the presentinvention, compression base valve 2010 is configured to generate aparticular threshold value. Hence, in such embodiments, compression basevalve 2010 can be described as having a selectable threshold value. Invarious embodiments of the present invention, compression base valve2010 is configured such that it has a non-zero threshold value.

Referring still to FIG. 7, in the present embodiment, compression basevalve 2010 includes various selectable flow paths as indicated by 2050 aand 2050 b. Embodiments of the present invention are well suited tohaving a greater or lesser number of various selectable flow pathswithin compression base valve 2010. Additionally, in embodiments of thepresent invention, pressure relief valve 2011 may also be considered asa selectable flow path of compression base valve 2010. The embodiment ofFIG. 7, as will be further described below, also includes a compressionadjustable interface 2016 which controls the selection between at leasttwo settings (e.g. between at least two of selectable flow paths 2050 aand 2050 b) for compression base valve 2010. It will be understood thata flow path, such as, for example, selectable flow path 2050 a and/orselectable flow path 2050 b refers to a particular fluidic path fordamping fluid to flow through the components which comprise compressionbase valve 2010. In one embodiment, a first fluidic path (e.g.selectable flow path 2050 a) will include a path through a first orificeof a component comprising compression base valve 2010 (see e.g., FIGS.16-19C discussed below), while a second fluidic path (e.g. selectableflow path 2050 b) will include a path through a second orifice ofcomponents comprising compression base valve 2010. In anotherembodiment, a first fluidic path (e.g. selectable flow path 2050 a) willinclude a path through a first component comprising compression basevalve 2010, while a second fluidic path (e.g. selectable flow path 2050b) will include a path through a second component comprising compressionbase valve 2010. That is, embodiments of the present invention, are wellsuited to various methods and structures for defining the variousselectable flow paths. Additionally, in embodiments of the presentinvention, various selectable paths (e.g. selectable flow path 2060 a)are also formed in a similar manner as described above for rebound basevalve 2014.

In one embodiment, compression base valve 2010 includes a pressurerelief valve 2011. In one such embodiment, pressure relief valve 2011 isdisposed to fluidically couple compression side 2003 and fluidaccumulator 2012 when the fluid pressure exceeds a pressure relief valvethreshold value. Pressure relief valve 2011, in one embodiment, preventshydrolock of twin tube shock 2001. For purposes of the presentapplication, compression base valve 2010 may be generally referred to asa flow control valve.

As schematically depicted within the dotted box enclosing rebound basevalve 2014, the present embodiment further comprises a rebound basevalve 2014. Rebound base valve 2014 is comprised of various valvecomponents which selectively fluidically couple rebound side 2005 andfluid accumulator 2012. It will be understood to those of ordinary skillin the art that rebound base valve 2014 can be comprised of any ofnumerous types of valve components or various configurations of suchvalve components. In the present embodiment, rebound base valve 2014includes a selectable flow path as indicated by 2060 a. Embodiments ofthe present invention are also well suited to having a greater or lessernumber of various selectable flow paths within rebound base valve 2014.In embodiments of the present invention, rebound base valve 2014 willallow the flow of fluid therethrough once the fluid pressure exceeds athreshold value for rebound base valve 2014. In various embodiments ofthe present invention, rebound base valve 2014 is configured such thatit has a non-zero threshold value. Also, for purposes of the presentapplication, rebound base valve 2014 may also be generally referred toas a flow control valve. Rebound base valve 2014 may be also generallybe referred to as an adjustable valve.

In various embodiments of the present invention, rebound base valve 2014is configured to generate a particular threshold value. Hence, in suchembodiments, rebound base valve 2014 can be described as having aselectable threshold value.

In another embodiment, rebound base valve 2014 includes a pressurerelief valve, not shown. The pressure relief valve is used in lieu of,or in addition to, pressure relief valve 2011, and fluidically couplesrebound side 2005 and fluid accumulator 2012 when the fluid pressureexceeds a pressure relief valve threshold value. The pressure reliefvalve, not shown, in one such embodiment, prevents hydrolock of twintube shock 2001.

With reference still to FIG. 7, as stated above, various embodiments ofthe present twin tube shock 2001 include a compression adjustableinterface 2016. Compression adjustable interface 2016 controls theselection between at least two settings (e.g. one of selectable flowpaths 2050 a and 2050 b) for compression base valve 2010. Hence, in suchan embodiment, compression base valve 2010 may be generally referred toas an adjustable valve. That is, compression adjustable interface 2016controls the fluidic coupling between compression side 2003 and fluidaccumulator 2012 by selectively determining the selectable flow path andthereby controlling the flow of fluid through the various components ofthe adjustable valve (compression base valve 2010). For purposes of thepresent application, the fluidic coupling between compression side 2003and fluid accumulator 2012 may be described as occurring along a fluidpathway extending between the first fluid volume (compression side 2003)and the accumulator fluid volume.

In some embodiments of the present invention, unlike with conventionaldampers, adjustments made to compression base valve 2010 via compressionadjustable interface 2016, do not affect rebound base valve 2014. Thatis, the selection of a particular selectable flow path (e.g. one ofselectable flow paths 2050 a and 2050 b) for compression base valve2010, does not alter the flow path of rebound base valve 2014. Hence, insuch an embodiment, compression base valve 2010 is independentlyadjustable and such an adjustment to compression base valve 2010 doesnot affect rebound base valve 2014.

In another embodiment of the present invention, compression adjustableinterface 2016 also controls the selection between settings for reboundbase valve 2014. That is, compression adjustable interface 2016 alsocontrols the fluidic coupling between rebound side 2005 and fluidaccumulator 2012 by selectively controlling the flow of fluid throughthe various components of the adjustable valve (rebound base valve2014). That is, in such an embodiment, the selection of a particularselectable flow path (e.g. one of selectable flow paths 2050 a and 2050b) for compression base valve 2010, also alters the flow path of reboundbase valve 2014. Hence, in such an embodiment, compression base valve2010 is not independently adjustable and such an adjustment tocompression base valve 2010 also affects rebound base valve 2014. Insuch an embodiment, compression adjustable interface 2016 and reboundadjustable interface 2018 may be coupled mechanically, hydraulically,pneumatically or through any other approach which will allow compressionadjustable interface 2016 and rebound adjustable interface 2018 to beoperated together.

For purposes of the present application, the fluidic coupling betweenrebound side 2005 and fluid accumulator 2012 may be described asoccurring along a fluid pathway extending between the second fluidvolume (rebound side 2005) and the accumulator fluid volume.

In one embodiment of the present invention, as previously describedherein, at least a second optional rebound adjustable interface 2018 isused in combination with compression adjustable interface 2016 tocontrol the fluidic coupling between fluid accumulator 2012 and one orboth of compression side 2003 and rebound side 2005. In one suchembodiment, compression adjustable interface 2016 controls fluidiccoupling, via compression base valve 2010, between compression side 2003and fluid accumulator 2012. Thus, compression adjustable interface 2016ultimately adjusts compression base valve 2010 (e.g., the thresholdvalue of compression base valve 2010, in one embodiment) and therebycontrols the flow of fluid along the fluid pathway extending between thefirst fluid volume (compression side 2003) and the accumulator fluidvolume. In one such embodiment, the adjustment of compression base valve2010 does not affect rebound base valve 2014.

Similarly, in one embodiment, rebound adjustable interface 2018 controlsfluidic coupling, via rebound base valve 2014, between rebound side 2005and fluid accumulator 2012. Thus, rebound adjustable interface 2018ultimately adjusts rebound base valve 2014 (e.g., the threshold value ofrebound base valve 2014, in one embodiment) and thereby controls theflow of fluid along the fluid pathway extending between the second fluidvolume (rebound side 2005) and the accumulator fluid volume. In one suchembodiment, the adjustment of rebound base valve 2014 does not affectcompression base valve 2010.

With reference still to FIG. 7, in one embodiment, when compressionadjustable interface 2016 is set at a restrictive compression base valvesetting (hard mode), compression adjustable interface 2016 also preventsfluid from flowing from the rebound side 2005 to fluid accumulator 2012through rebound base valve 2014. As a result, in such an embodiment,compression base valve 2010 controls the maximum possible thresholdforce (hard mode) for twin tube shock 2001. That is, in variousembodiments of the present invention, the maximum possible thresholdforce for twin tube shock 2001 is controlled by compression base valve2010, as selectively controlled by compression adjustable interface2016. Hence, in an embodiment of the present invention, damping pistonvalving 2008 of main damping piston 2006 is chosen such that is has anon-maximum compression damping setting. In such an embodiment, dampingpiston valving 2008 of main damping piston 2006 does not undesirablylimit the softness of the soft mode for twin tube shock 2001.

Referring now to FIG. 8, a back-perspective view of twin tube shock 2001of FIG. 7 is shown. In FIG. 8, external surfaces corresponding to maindamper body 2002 and fluid accumulator 2012 are shown. Additionally, inFIG. 8, the external surface of compression adjustable interface 2016 ofFIG. 7 is shown.

FIG. 9 is a cross-sectional view illustrating internal features of thepresent twin tube shock 2001.

FIG. 10 is a zoomed cross-sectional view illustrating internal featuressuch as the inner tube 102 damper and the outer tube 104 damper of oneembodiment of the present twin tube shock 2001.

FIG. 11A is a top view of the present twin tube shock 2001 including asection plane corresponding to the cross-sectional view provided in FIG.11B.

FIG. 11B is a cross-sectional view taken through the section plane shownin FIG. 11A. FIG. 11B shows a fluid connection path extending from themain damper body 2002 to the rebound base valve (schematically depictedas 2014 in FIG. 7).

FIG. 12A is a top view of the present twin tube shock 2001 including asection plane corresponding to the cross-sectional view provided in FIG.12B. FIG. 12B is a cross-sectional view taken through the section planeshown in FIG. 12A. FIG. 12B shows a fluid connection path extending fromthe main damper body 2002 to the compression base valve (schematicallydepicted as 2010 in FIG. 7).

FIG. 13A is a partial front perspective view of the present twin tubeshock 2001 including a section plane corresponding to thecross-sectional view provided in FIG. 13B. FIG. 13B is a cross-sectionalview taken through the section plane shown in FIG. 13A. FIG. 13B showsthe fluid connection path extending from the main damper body 2002 tothe rebound base valve (schematically depicted as 2014 in FIG. 7). FIG.13B further provides a view of various components comprising anembodiment of rebound base valve 2014. Embodiments of the presentinvention are also well suited to having rebound base valve 2014 becomprised of any of numerous types of valve components or variousconfigurations of such valve components.

FIG. 14A is a partial front perspective view of the present twin tubeshock 2001 including a section plane corresponding to thecross-sectional view provided in FIG. 14B. FIG. 14B is a cross-sectionalview taken through the section plane shown in FIG. 14A. FIG. 14B showsthe fluid connection path extending from the main damper body 2002 tothe compression base valve (schematically depicted as 2010 in FIG. 7).FIG. 14B further provides a view of various components comprising anembodiment of compression base valve 2010. Embodiments of the presentinvention are also well suited to having rebound base valve 2014 becomprised of any of numerous types of valve components or variousconfigurations of such valve components.

FIG. 15 is a cross-sectional view of a base valve including a selectorshaft. In one embodiment, selector shaft is coupled to, for example,compression adjustable interface 2016 of FIG. 7 to selectively controloperation of the compression base valve 2010. In another embodiment,selector shaft is coupled to, for example, rebound adjustable interface2018 of FIG. 7 to selectively control operation of the rebound basevalve 2014.

FIGS. 16 and 17 are perspective views of components comprising the basevalve shown in FIG. 15. FIG. 16 clearly shows various compression portsin the base valve. As stated above, in embodiments of the presentinvention, the various ports of FIG. 16 are used to define, for example,selectable flow path 2050 a and/or selectable flow path 2050 b of FIG. 7and FIG. 20. In one embodiment, a first fluidic path (e.g. selectableflow path 2050 a) will include a path through a first orifice or port ofthe valve of FIGS. 16 and 17, while a second fluidic path (e.g.selectable flow path 2050 b) will include a path through a secondorifice or port of the valve of FIGS. 16 and 17. Although a particularvalve type is depicted in FIG. 16, embodiments of the present inventionare also well suited to use with any of numerous other types of valvecomponents or various configurations of such valve components.

FIG. 17 also clearly shows various rebound ports in the base valve. Inembodiments of the present invention, the various ports of FIG. 16 areused to define, for example, selectable flow path 2060 a of FIG. 7 andFIG. 20. In one embodiment, a fluidic path (e.g. selectable flow path2060 a) will include a path through a first orifice or port of the valveof FIGS. 16 and 17, while a second fluidic path of rebound base valve2014 will include a path through a second orifice or port of the valveof FIGS. 16 and 17. Although a particular valve type is depicted in FIG.17, embodiments of the present invention are also well suited to usewith any of numerous other types of valve components or variousconfigurations of such valve components.

FIG. 18A is a perspective view of a base valve 1802. FIG. 18B is aperspective view of a selector valve 1804 for use with base valve 1802of FIG. 18A. FIG. 18C is a perspective view of base valve 1802 of FIG.18A having selector valve 1804 of FIG. 18B coupled thereto. In oneembodiment of the present invention, the location and/or orientation ofselector valve 1804 of 18B with respect to base valve 1802 is adjustedor set to define a particular fluidic path (e.g. selectable flow path2050 a of FIGS. 7 and 20) for compression base valve 2010. Similarly,one embodiment of the present invention, the location and/or orientationof selector valve 1804 of 18B with respect to base valve 1802 isadjusted or set to define a particular fluidic path (e.g. selectableflow path 2060 a of FIGS. 7 and 20) for rebound base valve 2014.

FIGS. 19A, 19B and 19C are perspective views of base valve 1802 of FIG.18A having selector valve 1804 of FIG. 18B oriented in various positionswith respect to base valve 1802, to selectively control the flow offluid through the combination of base valve 1802 and selector valve1804. Again, and as stated above, in one embodiment of the presentinvention, the location and/or orientation of selector valve 1804 of 18Bwith respect to base valve 1802 (as depicted in FIGS. 19A, 19B, and 19C)is adjusted or set to define a particular fluidic path (e.g. selectableflow path 2050 a or selectable flow path 2050 b of FIGS. 7 and 20) forcompression base valve 2010. Similarly, one embodiment of the presentinvention, the location and/or orientation of selector valve 1804 of 18Bwith respect to base valve 1802 (as depicted in FIGS. 19A, 19B, and 19C)is adjusted or set to define a particular fluidic path (e.g. selectableflow path 2060 a of FIGS. 7 and 20) for rebound base valve 2014.

Referring now to FIG. 20, another embodiment of the present invention isprovided. In the embodiment of FIG. 20, a controlled bypass fluid path2020 is created which extends between compression side 2003 and reboundside 2005 (i.e. around main damping piston 2006) but which does not flowthrough fluid accumulator 2012. In one embodiment of the presentinvention, at least a third optional internal bypass adjustableinterface 2021 is used to control the controlled bypass fluid path 2020.Hence, in the embodiment of FIG. 20, a fluid pathway fluidically couplesthe first fluid volume (e.g., compression side 2003) and the secondfluid volume (e.g., rebound side 2005) to enable fluid to flow aroundmain damping piston 2006 but without having the fluid pass through thefluid accumulator. In one embodiment, bypass openings such as, forexample, openings 110 a-d of FIG. 2 are used to achieve controlledbypass fluid path 2020.

In one embodiment of the present invention, an adjustable interface(such as compression adjustable interface 2016) is used to adjust thelocation and/or orientation of selector valve 1804 of 18B with respectto base valve 1802 (as depicted in FIGS. 19A, 19B, and 19C). Thus, insuch an embodiment, compression adjustable interface 2016 can be used toadjust the location and/or orientation of selector valve 1804 of 18Bwith respect to base valve 1802 to thereby set or define a particularfluidic path (e.g. selectable flow path 2050 a or selectable flow path2050 b of FIGS. 7 and 20) for compression base valve 2010.

In one embodiment of the present invention, an adjustable interface(such as rebound adjustable interface 2018) is used to adjust thelocation and/or orientation of selector valve 1804 of 18B with respectto base valve 1802 (as depicted in FIGS. 19A, 19B, and 19C). Thus, insuch an embodiment, rebound adjustable interface 2018 can be used toadjust the location and/or orientation of selector valve 1804 of 18Bwith respect to base valve 1802 to thereby set or define a particularfluidic path (e.g. selectable flow path 2060 a of FIGS. 7 and 20) forrebound base valve 2014.

Referring still to FIG. 20, in embodiments of the present invention,unlike with conventional dampers, adjustments made to compression basevalve 2010 via compression adjustable interface 2016, do not affectrebound base valve 2014 or controlled bypass fluid path 2020. That is,the selection of a particular selectable flow path (e.g. one ofselectable flow paths 2050 a and 2050 b) for compression base valve2010, does not alter the flow path of rebound base valve 2014 or affectcontrolled bypass fluid path 2020. Hence, in such an embodiment,compression base valve 2010 is independently adjustable and such anadjustment to compression base valve 2010 does not affect rebound basevalve 2014 or controlled bypass fluid path 2020.

In another embodiment of the present invention, compression adjustableinterface 2016 also controls the selection between settings for reboundbase valve 2014. That is, compression adjustable interface 2016 alsocontrols the fluidic coupling between rebound side 2005 and fluidaccumulator 2012 by selectively controlling the flow of fluid throughthe various components of the adjustable valve (rebound base valve2014). That is, in such an embodiment, the selection of a particularselectable flow path (e.g. one of selectable flow paths 2050 a and 2050b) for compression base valve 2010, also alters the flow path of reboundbase valve 2014. Hence, in such an embodiment, compression base valve2010 is not independently adjustable and such an adjustment tocompression base valve 2010 also affects rebound base valve 2014.

In still another embodiment of the present invention, compressionadjustable interface 2016 also controls the selection between settingsfor rebound base valve 2014 and controlled bypass fluid path 2020. Thatis, compression adjustable interface 2016 also controls the fluidiccoupling between rebound side 2005 and fluid accumulator 2012 byselectively controlling the flow of fluid through the various componentsof the adjustable valve (rebound base valve 2014), and also controls afluid pathway between the first fluid volume (e.g., compression side2003) and the second fluid volume (e.g., rebound side 2005) around maindamping piston 2006 without having the fluid pass through the fluidaccumulator. That is, in such an embodiment, the selection of aparticular selectable flow path (e.g. one of selectable flow paths 2050a and 2050 b) for compression base valve 2010, also affects the flowpath of rebound base valve 2014, and affects controlled bypass fluidpath 2020. Hence, in such an embodiment, compression base valve 2010 isnot independently adjustable and such an adjustment to compression basevalve 2010 affects rebound base valve 2014 and controlled bypass fluidpath 2020.

Thus, in various embodiments of the present invention, any two or moreof compression adjustable interface 2016, rebound adjustable interface2018, and internal bypass adjustable interface 2021 may be coupledmechanically, hydraulically, pneumatically or through any other approachwhich will allow the any two or more of compression adjustable interface2016, rebound adjustable interface 2018, and internal bypass adjustableinterface 2021 to be operated together.

Referring again to FIG. 20, in one embodiment, rebound adjustableinterface 2018 controls fluidic coupling, via rebound base valve 2014,between rebound side 2005 and fluid accumulator 2012. Thus, reboundadjustable interface 2018 ultimately adjusts rebound base valve 2014(e.g., the threshold value of rebound base valve 2014, in oneembodiment) and thereby controls the flow of fluid along the fluidpathway extending between the second fluid volume (rebound side 2005)and the accumulator fluid volume. In one such embodiment, the adjustmentof rebound base valve 2014 does not affect compression base valve 2010or controlled bypass fluid path 2020.

Referring still to FIG. 20, in one embodiment, internal bypassadjustable interface 2021 controls the controlled bypass fluid path2020. In one such embodiment, the adjustment of controlled bypass fluidpath 2020 does not affect compression base valve 2010 or rebound basevalve 2014.

With reference still to FIG. 20, in one embodiment, when compressionadjustable interface 2016 is set at a restrictive compression base valvesetting (hard mode), compression adjustable interface 2016 also preventsfluid from flowing from the rebound side 2005 to fluid accumulator 2012through rebound base valve 2014. As a result, in such an embodiment,compression base valve 2010 controls the maximum possible thresholdforce (hard mode) for twin tube shock 2001. That is, in variousembodiments of the present invention, the maximum possible thresholdforce for twin tube shock 2001 is controlled by compression base valve2010, as selectively controlled by compression adjustable interface2016. Hence, in an embodiment of the present invention, damping pistonvalving 2008 of main damping piston 2006 is chosen such that is has anon-maximum compression damping setting. In such an embodiment, dampingpiston valving 2008 of main damping piston 2006 does not undesirablylimit the softness of the soft mode for twin tube shock 2001.

The embodiment of FIG. 20 is utilized, in one example, only when it isdesired to place twin tube shock 2001 in a hard mode. In variousembodiments, when twin tube shock 2001 is in hard mode, rebound basevalve 2014 prevents the flow of fluid from rebound side 2005 into fluidaccumulator 2012. Under such conditions, fluid is only able to flow fromrebound side 2005 to compression side 2003 by flowing through dampingpiston valving 2008. However, in order to regulate rebound speeds duringtypical operation of twin tube shock 2001, damping piston valving 2008is typically designed to prevent rapid flow of fluid from rebound side2005 to compression side 2003. Thus, when rebound base valve 2014prevents the flow of fluid from rebound side 2005 into fluid accumulator2012 (e.g. in hard mode), fluid is not able to flow at the needed ratefrom rebound side 2005 to compression side 2003. In the presentembodiment, when twin tube shock 2001 is in hard mode, controlled bypassfluid path 2020 is opened and is used to enable fluid to flow morereadily from rebound side 2005 to compression side 2003. As a result,the present embodiment improves the speed of rebound even when twin tubeshock 2001 is in hard mode, and regardless of the stiffness orrestriction of rebound valving of main damping piston 2006.

In this discussion, the adjustable interface can be mechanical,electronic, pneumatic, and the like. In one embodiment, the adjustableinterface is externally adjustable such as by a user manipulating alever, switch, or the like. In one embodiment, the adjustable interfaceis internally adjustable via an electronic signal received at theadjustable interface which could electronically interact with theadjustable interface. The electronic signal could be received via awired or wireless configuration (e.g., NFC) and could be provided froman input provided by a user or automatically by a computer that ismonitoring the suspension component. As discussed herein, an adjustableinterface can refer to a single adjustable interface to open or close aflow path, a number of adjustable interfaces that work together toperform the function of opening or closing a flow path, etc. Forpurposes of clarity, the discussion will utilize the single adjustableinterface flow path control terminology with an understanding thatalthough the control is referred to as an adjustable interface, it couldalso be a plurality of adjustable interfaces that work in combination toachieve the same flow path state (e.g., open or closed).

In the following discussion of FIGS. 21-30, the description of thecomponents of FIGS. 21-30 that have been previously discussed in FIGS. 7and 20 are incorporated by reference and the discussions are notrepeated herein merely for purposes of clarity.

With reference now to FIG. 21, there are a number of locations where therebound adjustable interface 2018 can be located, but regardless of thelocation, the rebound adjustable interface 2018 is used, in oneembodiment, to not block, partially block, or completely block the flowpath from the rebound side 2005 of the main damping piston 2006 to thefluid accumulator 2012. Similarly, there are a number of locations wherethe compression adjustable interface 2016 can be located, but regardlessof the location, the compression adjustable interface 2016 is used, inone embodiment, to not block, partially block, or completely block theflow path from the compression side 2003 of the main damping piston 2006to the fluid accumulator 2012.

In one embodiment, the two adjustable interfaces 2016 and 2018 arecoupled (e.g., they act as a single adjustable interface). In anotherembodiment, the two adjustable interfaces 2016 and 2018 are separate(e.g., can be adjusted independently). In one embodiment, the reboundadjustable interface 2018 has three settings and the compressionadjustable interface 2016 also has three settings. In one embodiment, atleast one rebound setting is blocked by rebound adjustable interface2018.

With reference to FIG. 22, an additional controlled bypass fluid path2020 is shown about the main damping piston 2006. This is similar to thediscussion provided with respect to FIG. 21 except, the additionalcontrolled bypass fluid path 2020 provides an opportunity for aninternal bypass solution about main damping piston 2006. In one settingof internal bypass adjustable interface 2021 the flow path around themain damping piston 2006 is open (or active). In another setting ofinternal bypass adjustable interface 2021 the flow path around the maindamping piston 2006 is closed (or inactive). In FIG. 22, the threeadjustable interfaces could all be coupled (e.g., controlled via asingle adjustable interface), a combination of two of the adjustableinterfaces could be coupled and the remaining adjustable interface couldbe operated independently, or all three adjustable interfaces could beoperated separately (e.g., independently).

Referring to FIG. 23 an expanded notion to multiple positions of thecompression adjustable interface 2016. Thus, instead of only turning acompression adjustable interface 2016 on or off, the compressionadjustable interface 2016 has a number of positions to provide multiplecompression settings. In one embodiment, the rebound adjustableinterface 2018 also has a number of positions to provide multiplerebound settings. As such, the damping can be adjustable in one or moreways as a twin tube shock. Further, the rebound can be adjustable in oneor more ways as a twin tube shock.

In one embodiment, both compression adjustable interface 2016 andrebound adjustable interface 2018 of FIG. 23 include multiple positionssuch that the compression could be adjusted from full open to fullclosed, and similarly the rebound would be adjustable from full open tofull closed. In one embodiment, the two adjustable interfaces 2016 and2018 are operated separately (e.g., can be adjusted independently).

In one embodiment, both compression adjustable interface 2016 andrebound adjustable interface 2018 are coupled such that a singleadjustment to a shock setting results in a combined adjustment to bothcompression adjustable interface 2016 and rebound adjustable interface2018 (e.g., they act as a single adjustable interface). For example, inone embodiment there is a predetermined compression setting or settingsstructured in preparation for closing down the rebound circuit based onpredefined performance settings. For example, 1 through N−1 the multiposition on/off flow control valve (e.g., rebound adjustable interface2018) on the rebound side is open. From N to 1, the multi position onoff control valve would change states in the rebound base valve 2014.

In one embodiment, the two adjustable interfaces 2016 and 2018 arecoupled (e.g., they act as a single adjustable interface). In anotherembodiment, the two adjustable interfaces 2016 and 2018 are separate(e.g., can be adjusted independently). In one embodiment, the reboundadjustable interface 2018 has an arbitrary number of settings (e.g., 1through N) and the compression adjustable interface 2016 also has anarbitrary number of settings (e.g., 1 through N). In one embodiment, atleast one rebound setting is blocked by rebound adjustable interface2018.

FIG. 24 is similar to FIG. 23 except that FIG. 24 includes theadditional controlled bypass fluid path 2020 that bypasses the maindamping piston 2006 and is controlled by internal bypass adjustableinterface 2021. As previously described, this flow path provides aninternal bypass solution about main damping piston 2006. In one settingof internal bypass adjustable interface 2021 the flow path around themain damping piston 2006 is open (or active). In another setting ofinternal bypass adjustable interface 2021 the flow path around the maindamping piston 2006 is closed (or inactive). In FIG. 24, compressionadjustable interface 2016 has an arbitrary number of compressionsettings (1-N) and rebound adjustable interface 2018 has an arbitrarynumber of rebound settings (1-N). In FIG. 24, at least one reboundsetting is blocked. In FIG. 24, the three adjustable interfaces couldall be coupled (e.g., controlled via a single adjustable interface), acombination of two of the adjustable interfaces could be coupled and theremaining adjustable interface could be operated independently, or allthree adjustable interfaces could be operated separately (e.g.,independently).

In the following discussion of FIGS. 25-30, the description of thecomponents of FIGS. 25-30 that have been previously discussed in FIGS. 7and 21 are incorporated by reference and the discussions are notrepeated herein merely for purposes of clarity.

With reference now to FIG. 25, there are a number of locations where therebound adjustable interface 2018 can be located, but regardless of thelocation, the rebound adjustable interface 2018 is used, in oneembodiment, to not block, partially block, or completely block the flowpath between the fluid accumulator 2012 and the rebound side 2005 of themain damping piston 2006. Thus, there is a first position (e.g., open)for rebound adjustable interface 2018 that causes the shock to operatelike a twin tube shock, and there is at least a second position (e.g.,closed) for rebound adjustable interface 2018 that causes the shock tooperate like a mono tube shock.

In one embodiment, the location of the rebound adjustable interface 2018(on/off or multi-setting) is shown on the damper body side of theone-way valve and rebound circuit as opposed to the previous Figureswhere it was on the opposite side of this circuit from the damper body.E.g., downstream from the rebound circuit instead of being upstream fromthe rebound circuit. In one embodiment, the rebound adjustable interface2018 location could be upstream or downstream from any valving betweenthe damper body 2002 and the fluid accumulator 2012.

In FIG. 25, the setting of rebound adjustable interface 2018 iseffectively a monotube in one setting and a twin tube in the other. Inone embodiment, the two adjustable interfaces 2016 and 2018 are coupled(e.g., they act as a single adjustable interface). In anotherembodiment, the two adjustable interfaces 2016 and 2018 are separate(e.g., can be adjusted independently). In one embodiment, the reboundconnection to the fluid accumulator 2012 is toggled with the flowcontrol valve (e.g., rebound adjustable interface 2018 is either openedor closed—thereby causing the shock to act as a monotube or twin tube).In one embodiment, the compression adjustable interface 2016 has twopositions.

FIG. 26 is similar to FIG. 25 except that FIG. 26 includes theadditional controlled bypass fluid path 2020 that bypasses the maindamping piston 2006 and is controlled by internal bypass adjustableinterface 2021. As previously described, this flow path provides aninternal bypass solution about main damping piston 2006. In one settingof internal bypass adjustable interface 2021 the flow path around themain damping piston 2006 is open (or active). In another setting ofinternal bypass adjustable interface 2021 the flow path around the maindamping piston 2006 is closed (or inactive). In FIG. 26, the threeadjustable interfaces could all be coupled (e.g., controlled via asingle adjustable interface), a combination of two of the adjustableinterfaces could be coupled and the remaining adjustable interface couldbe operated independently, or all three adjustable interfaces could beoperated separately (e.g., independently).

Referring now to FIG. 27, the location of the rebound adjustableinterface 2018 (on/off or multi-setting) is also moved to the damperbody side of the one-way valve and rebound circuit as described in FIG.25. E.g., downstream from the rebound circuit instead of being upstreamfrom the rebound circuit. In one embodiment, the rebound adjustableinterface 2018 location could be upstream or downstream from any valvingbetween the damper body 2002 and the fluid accumulator 2012. In FIG. 27,the setting of rebound adjustable interface 2018 is a multi-positionadjustable interface having an arbitrary number of settings. In oneembodiment, the compression adjustable interface 2016 also has anarbitrary number of positions. In one embodiment, the two adjustableinterfaces 2016 and 2018 are coupled (e.g., they act as a singleadjustable interface). In another embodiment, the two adjustableinterfaces 2016 and 2018 are separate (e.g., can be adjustedindependently).

FIG. 28 is similar to FIG. 27 except that FIG. 28 includes theadditional controlled bypass fluid path 2020 that bypasses the maindamping piston 2006 and is controlled by internal bypass adjustableinterface 2021. As previously described, this flow path provides aninternal bypass solution about main damping piston 2006. In one settingof internal bypass adjustable interface 2021 the flow path around themain damping piston 2006 is open (or active). In another setting ofinternal bypass adjustable interface 2021 the flow path around the maindamping piston 2006 is closed (or inactive). In FIG. 28, the threeadjustable interfaces could all be coupled (e.g., controlled via asingle adjustable interface), a combination of two of the adjustableinterfaces could be coupled and the remaining adjustable interface couldbe operated independently, or all three adjustable interfaces could beoperated separately (e.g., independently).

Referring now to FIG. 29, the location of the rebound adjustableinterface 2018 (on/off or multi-setting) is moved upstream from therebound circuit instead of being downstream from the rebound circuit. Inone embodiment, the rebound adjustable interface 2018 location could beupstream or downstream from any valving between the damper body 2002 andthe fluid accumulator 2012. In FIG. 29, the setting of reboundadjustable interface 2018 could be an on/off or a multi-positionadjustable interface having an arbitrary number of settings. In oneembodiment, the compression adjustable interface 2016 also has anarbitrary number of positions. In one embodiment, the two adjustableinterfaces 2016 and 2018 are coupled (e.g., they act as a singleadjustable interface). In another embodiment, the two adjustableinterfaces 2016 and 2018 are separate (e.g., can be adjustedindependently). In one embodiment, the rebound connection to the fluidaccumulator 2012 is toggled with rebound adjustable interface 2018.

FIG. 30 is similar to FIG. 29 except that FIG. 30 includes theadditional controlled bypass fluid path 2020 that bypasses the maindamping piston 2006 and is controlled by internal bypass adjustableinterface 2021. As previously described, this flow path provides aninternal bypass solution about main damping piston 2006. In one settingof internal bypass adjustable interface 2021 the flow path around themain damping piston 2006 is open (or active). In another setting ofinternal bypass adjustable interface 2021 the flow path around the maindamping piston 2006 is closed (or inactive). In FIG. 30, the threeadjustable interfaces could all be coupled (e.g., controlled via asingle adjustable interface), a combination of two of the adjustableinterfaces could be coupled and the remaining adjustable interface couldbe operated independently, or all three adjustable interfaces could beoperated separately (e.g., independently). In one embodiment, therebound connection to the fluid accumulator 2012 is toggled with reboundadjustable interface 2018.

Use Case Examples

With reference again to FIG. 25, two compression circuits that areadjustable by compression adjustable interface 2016 and an on off flowcontrol valve on the rebound side controlled by rebound adjustableinterface 2018 is shown. Compression setting 1 would be an open modesetting, e.g., a damper setting used when going downhill (e.g., a lessdamped setting). When rebound adjustable interface 2018 is in theposition to allow flow through the rebound base valve 2014, the damperacts as a twin tube damper. In one embodiment, flow can go through thedamper body 2002 through the compression circuit one into theaccumulator any amount of overflow from the shaft displaced oil can flowthrough the one-way valve and back into the rebound side of the bodylike a twin tube shock.

In a climb mode, e.g., a firmer setting, compression adjustableinterface 2016 would be set to the compression mode 2 (e.g., a moreheavily damped state). In one embodiment, the position of thecompression adjustable interface 2016 on the compression 2010 would alsochange the position of rebound adjustable interface 2018 on the reboundbase valve 2014. When rebound adjustable interface 2018 is in theposition to close the flow through the rebound base valve 2014, thedamper 2002 is no longer fluidly connected on the rebound side 2005 tothe fluid accumulator 2012. In so doing, the damper will act like amonotube shock, such that shaft displaced fluid goes to the fluidaccumulator 2012 and that is the only amount of fluid that can go to thefluid accumulator 2012.

In general, closing the fluid flow through the rebound side 2005, allowsfor easier tuning of a heavily damped shocking system. In other words, amuch firmer setting for the shock can be obtained without affectingsubsequent operation. In so doing, the compression range for the damperis expanded from its most firm to its least firm setting.

In FIG. 25 (and similarly FIGS. 27 and 29), the number of states of thedamper can be adjusted anywhere from 1 to N. In one embodiment, thestates could be open, middle, or firm mode in a three-mode system (or aplurality of different modes, states, etc.). In the open or middle mode,the damper is configured to act like a twin tube shock. In the firmmode, the damper is configured to act like a mono tube shock. Thesesettings could include the setting of the rebound adjustable interface2018 to a plurality of different flow values through the rebound sidefrom a closed position through a number of different flow values all theway to a completely open rebound flow value. In one embodiment, thesettings of the rebound adjustable interface 2018 would be related tothe different flow values of the compression adjustable interface 2016.In another embodiment, the settings of the rebound adjustable interface2018 would be distinct from the different flow values of the compressionadjustable interface 2016.

Adding on the operation of the Figures including the internal bypass(e.g., FIGS. 26, 28, and 30), when the internal bypass adjustableinterface 2021 is used. Using the internal bypass allows the open modeto have an even softer setting. For example, when the shock is in a monotube configuration the closing of the internal bypass fluid path 2020will provide further stiffness. In contrast, when the shock is in a twintube configuration the opening of the internal bypass fluid path 2020will provide additional softness. In one embodiment, the internal bypassis position dependent. For example, the internal bypass flow path couldbe opened or closed depending on weather the damper is fully extended,fully compressed, or at another pre-defined operational location of thedamper system.

In one embodiment, the setting (or adjusting) of the compressionadjustable interface 2016 and/or rebound adjustable interface 2018 aremanually input by a user. As such, the setting could be adjusted basedon a transition between terrain types, e.g., downhill, flat, climb,etc., environment types, e.g., wet, dry, sandy, hardpack, road, etc.,performance types, e.g., tricks, stability, etc., or any otheron-the-fly transitioning situation where the rider desires a change inshock stiffness.

In one embodiment, the setting or adjusting of compression adjustableinterface 2016, rebound adjustable interface 2018 and/or internal bypassadjustable interface 2021, are electronically made via an electronicinput from a suspension system that is electronically coupled withcompression adjustable interface 2016 and/or rebound adjustableinterface 2018. As such, the setting could be electronically adjusted ata transition between terrain types, e.g., downhill, flat, climb, etc.,environment types, e.g., wet, dry, sandy, hardpack, road, etc.,performance types, e.g., tricks, stability, etc., or any otheron-the-fly transitioning situation where the electronic suspensionsystem (or system feedback) determines that a change in shock stiffnesswould provide the best damping performance. The electronic adjustmentscould be real-time, could be continuously adjusted based on themonitoring of performance, environment, and the like.

Additionally, in various embodiments, one or more of compressionadjustable interface 2016, rebound adjustable interface 2018, andinternal bypass adjustable interface 2021 (referred to in the followingdiscussion in a singular form “compression adjustable interface 2016”for purposes of clarity, but capable of being applied to each, acombination, or all of the adjustable interfaces) are powered such thatit is operable, for example, by a user selectable switch locatedremotely from the twin tube shock 2001. In one such embodiment, a powersource, on the vehicle utilizing twin tube shock 2001, is used tocontrol the operation of compression adjustable interface 2016.Additionally, in such an embodiment, compression adjustable interface2016 may or may not remain manually adjustable as previously described.Hydraulically actuated valving for use with additional components (suchas, for example, compression adjustable interface 2016) is shown anddescribed in U.S. Pat. No. 6,073,536 and that patent is incorporated byreference herein in its entirety. A variety of means are available forremotely controlling compression adjustable interface 2016. Forinstance, a source of electrical power from a 12-volt battery could beused to operate a solenoid member, thereby shifting the position ofcompression adjustable interface 2016. The valve or solenoid operatingsignal can be either via a physical conductor or an RF signal (or otherwireless such as Bluetooth, WiFi, ANT) from a transmitter operated by aswitch to a receiver operable on the compression adjustable interface2016 (which would derive power from the vehicle power system such as 12volt).

A remotely operable compression adjustable interface 2016 like the onedescribed above is particularly useful with an on/off road vehicle.These vehicles can have as much as 20″ of shock absorber travel topermit them to negotiate rough, uneven terrain at speed with usableshock absorbing function. In off-road applications, compliant dampeningis necessary as the vehicle relies on its long travel suspension whenencountering often large off-road obstacles. Operating a vehicle withvery compliant, long travel suspension on a smooth road at higher speedscan be problematic due to the springiness/sponginess of the suspensionand corresponding vehicle handling problems associated with that (e.g.turning roll, braking pitch). Such compliance can cause reduced handlingcharacteristics and even loss of control. Such control issues can bepronounced when cornering at high speed as a compliant, long travelvehicle may tend to roll excessively. Similarly, such a vehicle maypitch and yaw excessively during braking and acceleration. With theremotely operated compression adjustable interface 2016 describedherein, dampening characteristics of a shock absorber can be completelychanged from a compliantly dampened “springy” arrangement to a highlydampened and “stiffer” (or fully locked out) system ideal for higherspeeds on a smooth road.

In addition to, or in lieu of, the manual operation of compressionadjustable interface 2016, compression adjustable interface 2016 can beoperated automatically based upon one or more driving conditions. Thesedriving conditions include, but are not limited to any or all of,vehicle speed, damper rod speed, and damper rod position. One embodimentof the present invention is designed to automatically increase dampeningin the twin tube shock absorber in the event a damper rod reaches acertain velocity in its travel towards the bottom end of a damper at apredetermined speed of the vehicle. In one embodiment, the system addsdampening (and control) in the event of rapid operation (e.g. high rodvelocity) of the damper to avoid a bottoming out of the damper rod aswell as a loss of control that can accompany rapid compression of ashock absorber with a relative long amount of travel. In one embodimentthe system adds dampening (e.g. changes the setting of compressionadjustable interface 2016) in the event that the rod velocity incompression is relatively low, but the rod progresses past a certainpoint in the travel. Such configuration aids in stabilizing the vehicleagainst excessive low rate suspension movement events such as corneringroll, braking and acceleration yaw and pitch and “g-out.”

Any other suitable vehicle operation variable may be used such as forexample piston rod compression strain, eyelet strain, vehicle mountedaccelerometer (or tilt/inclinometer) data or any other suitable vehicleor component performance data. In one embodiment, the position of maindamping piston 2006 within twin tube shock 2001 is determined using anaccelerometer to sense modal resonance of main damper body 2002. Suchresonance will change depending on the position of main damping piston2006 and an on-board processor (computer) is calibrated to correlateresonance with axial position. In one embodiment, a suitable proximitysensor or linear coil transducer or other electro-magnetic transducer isincorporated in the dampening cylinder to provide a sensor to monitorthe position and/or speed of the main damping piston 2006 (and suitablemagnetic tag) with respect to main damper body 2002. In one embodiment,the magnetic transducer includes a waveguide and a magnet, such as adoughnut (toroidal) magnet that is joined to main damper body 2002 andoriented such that the magnetic field generated by the magnet passesthrough damper shaft 2004 and the waveguide. Electric pulses are appliedto the waveguide from a pulse generator that provides a stream ofelectric pulses, each of which is also provided to a signal processingcircuit for timing purposes. When the electric pulse is applied to thewaveguide a magnetic field is formed surrounding the waveguide.Interaction of this field with the magnetic field from the magnet causesa torsional strain wave pulse to be launched in the waveguide in bothdirections away from the magnet. A coil assembly and sensing tape isjoined to the waveguide. The strain wave causes a dynamic effect in thepermeability of the sensing tape which is biased with a permanentmagnetic field by the magnet. The dynamic effect in the magnetic fieldof the coil assembly due to the strain wave pulse, results in an outputsignal from the coil assembly that is provided to the signal processingcircuit along signal lines. By comparing the time of application of aparticular electric pulse and a time of return of a sonic torsionalstrain wave pulse back along the waveguide, the signal processingcircuit can calculate a distance of the magnet from the coil assembly orthe relative velocity between the waveguide and the magnet. The signalprocessing circuit provides an output signal, either digital, or analog,proportional to the calculated distance and/or velocity. Atransducer-operated arrangement for measuring piston rod (or dampershaft) speed and velocity is described in U.S. Pat. No. 5,952,823 andthat patent is incorporated by reference herein in its entirety.

While a transducer assembly located at the main damper body measuresdamper shaft/rod speed and location, a separate wheel speed transducerfor sensing the rotational speed of a wheel about an axle includeshousing fixed to the axle and containing therein, for example, twopermanent magnets. In one embodiment, the magnets are arranged such thatan elongated pole piece commonly abuts first surfaces of each of themagnets, such surfaces being of like polarity. Two inductive coilshaving flux-conductive cores axially passing therethrough abut each ofthe magnets on second surfaces thereof, the second surfaces of themagnets again being of like polarity with respect to each other and ofopposite polarity with respect to the first surfaces. Wheel speedtransducers are described in U.S. Pat. No. 3,986,118 which isincorporated herein by reference in its entirety.

In one embodiment, a logic unit with user-definable settings receivesinputs from the rod speed and location transducers as well as the wheelspeed transducer. The logic unit is user-programmable and depending onthe needs of the operator, the unit records the variables and then ifcertain criteria are met, the logic circuit sends its own signal to thecompression adjustable interface 2016. Thereafter, the condition of thecompression adjustable interface 2016 is relayed back to the logic unit.

Example embodiments of the subject matter are thus described. Althoughthe subject matter has been described in a language specific tostructural features and/or methodological acts, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the specific features or acts described above.Rather, the specific features and acts described above are disclosed asexample forms of implementing the claims.

Various embodiments have been described in various combinations andillustrations. However, any two or more embodiments or features may becombined. Further, any embodiment or feature may be used separately fromany other embodiment or feature. Phrases, such as “an embodiment,” “oneembodiment,” among others, used herein, are not necessarily referring tothe same embodiment. Features, structures, or characteristics of anyembodiment may be combined in any suitable manner with one or more otherfeatures, structures, or characteristics.

What is claimed is:
 1. A fluid damper comprising: a damper housinghaving a first fluid volume and a second fluid volume; a damping pistonreciprocatingly disposed within said damper housing and separating saidfirst fluid volume from said second fluid volume; a piston fluid pathwaybetween said first fluid volume and said second fluid volume throughsaid damping piston; a fluid accumulator having an accumulator fluidvolume; a first fluid pathway extending between said first fluid volumeand said accumulator fluid volume, the first fluid pathway to providecompression characteristics; a second fluid pathway extending betweensaid second fluid volume and said accumulator fluid volume, the secondfluid pathway to provide rebound characteristics; a first adjustablevalve, said first adjustable valve disposed in said first fluid pathway,said first adjustable valve to adjust a compression characteristic ofsaid fluid damper; and a second adjustable valve, said second adjustablevalve disposed in said second fluid pathway, said second adjustablevalve to adjust a rebound characteristic of said fluid damper.
 2. Thefluid damper of claim 1 wherein the fluid accumulator further comprises:a pressurizable gas volume, the pressurizable gas volume isolated fromthe accumulator fluid volume by a separation member.
 3. The fluid damperof claim 1 wherein a closing of the second adjustable valve causes thefluid damper to act as a mono tube damper.
 4. The fluid damper of claim1 wherein an opening of the second adjustable valve causes the fluiddamper to act as a twin tube damper.
 5. The fluid damper of claim 1wherein the first adjustable valve is operable independent of the secondadjustable valve; and the second adjustable valve is operableindependent of the first adjustable valve.
 6. The fluid damper of claim1 wherein the first adjustable valve is coupled with the secondadjustable valve and acts as a single adjustable interface.
 7. The fluiddamper of claim 1 further comprising: an externally adjustable interfacecoupled with one or both of said first adjustable valve and said secondadjustable valve, the externally adjustable interface able to bemanually manipulated by a user to change a setting of at least one ofsaid first adjustable valve and said second adjustable valve.
 8. Thefluid damper of claim 1 further comprising: an internally adjustableelectronic interface coupled with one or both of said first adjustablevalve and said second adjustable valve, the internally adjustableelectronic interface capable of electronically changing a setting of atleast one of said first adjustable valve and said second adjustablevalve.
 9. A fluid damper comprising: a damper housing having a firstfluid volume and a second fluid volume; a damping piston reciprocatinglydisposed within said damper housing and separating said first fluidvolume from said second fluid volume; a piston fluid pathway betweensaid first fluid volume and said second fluid volume through saiddamping piston; a fluid accumulator having an accumulator fluid volume;a plurality of first fluid pathways extending between said first fluidvolume and said accumulator fluid volume, the plurality of first fluidpathways to provide compression characteristics; a second fluid pathwaysextending between said second fluid volume and said accumulator fluidvolume, the second fluid pathway to provide rebound characteristics; afirst adjustable valve to adjust a compression characteristic of saidfluid damper, the first adjustable valve controlling a compression fluidflow through each of the plurality of first fluid pathways; and a secondadjustable valve, said second adjustable valve disposed in said secondfluid pathway, said second adjustable valve to adjust a reboundcharacteristic of said fluid damper.
 10. The fluid damper of claim 9wherein the fluid accumulator further comprises: a pressurizable gasvolume, the pressurizable gas volume isolated from the accumulator fluidvolume by a separation member.
 11. The fluid damper of claim 9 wherein aclosing of the second adjustable valve causes the fluid damper to act asa mono tube damper.
 12. The fluid damper of claim 9 wherein an openingof the second adjustable valve causes the fluid damper to act as a twintube damper.
 13. The fluid damper of claim 9 wherein the firstadjustable valve is operable independent of the second adjustable valve;and the second adjustable valve is operable independent of the firstadjustable valve.
 14. The fluid damper of claim 9 wherein the firstadjustable valve is coupled with the second adjustable valve and acts asa single adjustable interface.
 15. The fluid damper of claim 9 furthercomprising: an externally adjustable interface coupled with one or bothof said first adjustable valve and said second adjustable valve, theexternally adjustable interface able to be manually manipulated by auser to change a setting of at least one of said first adjustable valveand said second adjustable valve.
 16. The fluid damper of claim 9further comprising: an internally adjustable electronic interfacecoupled with one or both of said first adjustable valve and said secondadjustable valve, the internally adjustable electronic interface capableof electronically changing a setting of at least one of said firstadjustable valve and said second adjustable valve.
 17. A fluid dampercomprising: a damper housing having a first fluid volume and a secondfluid volume; a damping piston reciprocatingly disposed within saiddamper housing and separating said first fluid volume from said secondfluid volume; a piston fluid pathway between said first fluid volume andsaid second fluid volume through said damping piston; a fluidaccumulator having an accumulator fluid volume; a plurality of firstfluid pathways extending between said first fluid volume and saidaccumulator fluid volume, the plurality of first fluid pathways toprovide compression characteristics; a plurality of second fluidpathways extending between said second fluid volume and said accumulatorfluid volume, the plurality of second fluid pathways to provide reboundcharacteristics; a first adjustable valve to adjust at least onecompression characteristic of said fluid damper, the first adjustablevalve controlling a compression fluid flow through each of the pluralityof first fluid pathways; and a second adjustable valve to adjust atleast one rebound characteristic of said fluid damper, the firstadjustable valve controlling a rebound fluid flow through each of theplurality of first fluid pathways.
 18. The fluid damper of claim 17wherein the first adjustable valve is operable independent of the secondadjustable valve; and the second adjustable valve is operableindependent of the first adjustable valve.
 19. The fluid damper of claim17 further comprising: an externally adjustable interface coupled withone or both of said first adjustable valve and said second adjustablevalve, the externally adjustable interface able to be manuallymanipulated by a user to change a setting of at least one of said firstadjustable valve and said second adjustable valve.
 20. The fluid damperof claim 17 further comprising: an internally adjustable electronicinterface coupled with one or both of said first adjustable valve andsaid second adjustable valve, the internally adjustable electronicinterface capable of electronically changing a setting of at least oneof said first adjustable valve and said second adjustable valve.